/** @file
  This library parses the INI configuration file.

  The INI file format is:
    ================
    [SectionName]
    EntryName=EntryValue
    ================

    Where:
      1) SectionName is an ASCII string. The valid format is [A-Za-z0-9_]+
      2) EntryName is an ASCII string. The valid format is [A-Za-z0-9_]+
      3) EntryValue can be:
         3.1) an ASCII String. The valid format is [A-Za-z0-9_]+
         3.2) a GUID. The valid format is xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx, where x is [A-Fa-f0-9]
         3.3) a decimal value. The valid format is [0-9]+
         3.4) a heximal value. The valid format is 0x[A-Fa-f0-9]+
      4) '#' or ';' can be used as comment at anywhere.
      5) TAB(0x20) or SPACE(0x9) can be used as separator.
      6) LF(\n, 0xA) or CR(\r, 0xD) can be used as line break.

  Caution: This module requires additional review when modified.
  This driver will have external input - INI data file.

  OpenIniFile(), PreProcessDataFile(), ProfileGetSection(), ProfileGetEntry()
  will receive untrusted input and do basic validation.

  Copyright (c) 2016 - 2017, Intel Corporation. All rights reserved.<BR>

  This program and the accompanying materials
  are licensed and made available under the terms and conditions
  of the BSD License which accompanies this distribution.  The
  full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

#include <Uefi.h>
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Library/MemoryAllocationLib.h>

#define IS_HYPHEN(a)               ((a) == '-')
#define IS_NULL(a)                 ((a) == '\0')

// This is default allocation. Reallocation will happen if it is not enough.
#define MAX_LINE_LENGTH           512

typedef struct _INI_SECTION_ITEM SECTION_ITEM;
struct _INI_SECTION_ITEM {
  CHAR8                           *PtrSection;
  UINTN                           SecNameLen;
  CHAR8                           *PtrEntry;
  CHAR8                           *PtrValue;
  SECTION_ITEM                    *PtrNext;
};

typedef struct _INI_COMMENT_LINE COMMENT_LINE;
struct _INI_COMMENT_LINE {
  CHAR8                           *PtrComment;
  COMMENT_LINE                    *PtrNext;
};

typedef struct {
  SECTION_ITEM                  *SectionHead;
  COMMENT_LINE                  *CommentHead;
} INI_PARSING_LIB_CONTEXT;

/**
  Return if the digital char is valid.

  @param[in] DigitalChar    The digital char to be checked.
  @param[in] IncludeHex     If it include HEX char.

  @retval TRUE   The digital char is valid.
  @retval FALSE  The digital char is invalid.
**/
BOOLEAN
IsValidDigitalChar (
  IN CHAR8    DigitalChar,
  IN BOOLEAN  IncludeHex
  )
{
  if (DigitalChar >= '0' && DigitalChar <= '9') {
    return TRUE;
  }
  if (IncludeHex) {
    if (DigitalChar >= 'a' && DigitalChar <= 'f') {
      return TRUE;
    }
    if (DigitalChar >= 'A' && DigitalChar <= 'F') {
      return TRUE;
    }
  }
  return FALSE;
}

/**
  Return if the name char is valid.

  @param[in] NameChar    The name char to be checked.

  @retval TRUE   The name char is valid.
  @retval FALSE  The name char is invalid.
**/
BOOLEAN
IsValidNameChar (
  IN CHAR8  NameChar
  )
{
  if (NameChar >= 'a' && NameChar <= 'z') {
    return TRUE;
  }
  if (NameChar >= 'A' && NameChar <= 'Z') {
    return TRUE;
  }
  if (NameChar >= '0' && NameChar <= '9') {
    return TRUE;
  }
  if (NameChar == '_') {
    return TRUE;
  }
  return FALSE;
}

/**
  Return if the digital string is valid.

  @param[in] Digital        The digital to be checked.
  @param[in] Length         The length of digital string in bytes.
  @param[in] IncludeHex     If it include HEX char.

  @retval TRUE   The digital string is valid.
  @retval FALSE  The digital string is invalid.
**/
BOOLEAN
IsValidDigital (
  IN CHAR8    *Digital,
  IN UINTN    Length,
  IN BOOLEAN  IncludeHex
  )
{
  UINTN  Index;
  for (Index = 0; Index < Length; Index++) {
    if (!IsValidDigitalChar(Digital[Index], IncludeHex)) {
      return FALSE;
    }
  }
  return TRUE;
}

/**
  Return if the decimal string is valid.

  @param[in] Decimal The decimal string to be checked.
  @param[in] Length  The length of decimal string in bytes.

  @retval TRUE   The decimal string is valid.
  @retval FALSE  The decimal string is invalid.
**/
BOOLEAN
IsValidDecimalString (
  IN CHAR8  *Decimal,
  IN UINTN  Length
  )
{
  return IsValidDigital(Decimal, Length, FALSE);
}

/**
  Return if the heximal string is valid.

  @param[in] Hex     The heximal string to be checked.
  @param[in] Length  The length of heximal string in bytes.

  @retval TRUE   The heximal string is valid.
  @retval FALSE  The heximal string is invalid.
**/
BOOLEAN
IsValidHexString (
  IN CHAR8  *Hex,
  IN UINTN  Length
  )
{
  if (Length <= 2) {
    return FALSE;
  }
  if (Hex[0] != '0') {
    return FALSE;
  }
  if (Hex[1] != 'x' && Hex[1] != 'X') {
    return FALSE;
  }
  return IsValidDigital(&Hex[2], Length - 2, TRUE);
}

/**
  Return if the name string is valid.

  @param[in] Name    The name to be checked.
  @param[in] Length  The length of name string in bytes.

  @retval TRUE   The name string is valid.
  @retval FALSE  The name string is invalid.
**/
BOOLEAN
IsValidName (
  IN CHAR8  *Name,
  IN UINTN  Length
  )
{
  UINTN  Index;
  for (Index = 0; Index < Length; Index++) {
    if (!IsValidNameChar(Name[Index])) {
      return FALSE;
    }
  }
  return TRUE;
}

/**
  Return if the value string is valid GUID.

  @param[in] Value   The value to be checked.
  @param[in] Length  The length of value string in bytes.

  @retval TRUE   The value string is valid GUID.
  @retval FALSE  The value string is invalid GUID.
**/
BOOLEAN
IsValidGuid (
  IN CHAR8  *Value,
  IN UINTN  Length
  )
{
  if (Length != sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx") - 1) {
    return FALSE;
  }
  if (!IS_HYPHEN(Value[8])) {
    return FALSE;
  }
  if (!IS_HYPHEN(Value[13])) {
    return FALSE;
  }
  if (!IS_HYPHEN(Value[18])) {
    return FALSE;
  }
  if (!IS_HYPHEN(Value[23])) {
    return FALSE;
  }
  if (!IsValidDigital(&Value[0], 8, TRUE)) {
    return FALSE;
  }
  if (!IsValidDigital(&Value[9], 4, TRUE)) {
    return FALSE;
  }
  if (!IsValidDigital(&Value[14], 4, TRUE)) {
    return FALSE;
  }
  if (!IsValidDigital(&Value[19], 4, TRUE)) {
    return FALSE;
  }
  if (!IsValidDigital(&Value[24], 12, TRUE)) {
    return FALSE;
  }
  return TRUE;
}

/**
  Return if the value string is valid.

  @param[in] Value    The value to be checked.
  @param[in] Length  The length of value string in bytes.

  @retval TRUE   The name string is valid.
  @retval FALSE  The name string is invalid.
**/
BOOLEAN
IsValidValue (
  IN CHAR8  *Value,
  IN UINTN  Length
  )
{
  if (IsValidName(Value, Length) || IsValidGuid(Value, Length)) {
    return TRUE;
  }
  return FALSE;
}

/**
  Dump an INI config file context.

  @param[in] Context         INI Config file context.
**/
VOID
DumpIniSection (
  IN VOID  *Context
  )
{
  INI_PARSING_LIB_CONTEXT               *IniContext;
  SECTION_ITEM                          *PtrSection;
  SECTION_ITEM                          *Section;

  if (Context == NULL) {
    return;
  }

  IniContext = Context;
  Section = IniContext->SectionHead;

  while (Section != NULL) {
    PtrSection = Section;
    Section = Section->PtrNext;
    if (PtrSection->PtrSection != NULL) {
      DEBUG((DEBUG_VERBOSE, "Section - %a\n", PtrSection->PtrSection));
    }
    if (PtrSection->PtrEntry != NULL) {
      DEBUG ((DEBUG_VERBOSE, "  Entry - %a\n", PtrSection->PtrEntry));
    }
    if (PtrSection->PtrValue != NULL) {
      DEBUG((DEBUG_VERBOSE, "  Value - %a\n", PtrSection->PtrValue));
    }
  }
}

/**
  Copy one line data from buffer data to the line buffer.

  @param[in]      Buffer          Buffer data.
  @param[in]      BufferSize      Buffer Size.
  @param[in, out] LineBuffer      Line buffer to store the found line data.
  @param[in, out] LineSize        On input, size of the input line buffer.
                                  On output, size of the actual line buffer.

  @retval EFI_BUFFER_TOO_SMALL  The size of input line buffer is not enough.
  @retval EFI_SUCCESS           Copy line data into the line buffer.

**/
EFI_STATUS
ProfileGetLine (
  IN      UINT8                         *Buffer,
  IN      UINTN                         BufferSize,
  IN OUT  UINT8                         *LineBuffer,
  IN OUT  UINTN                         *LineSize
  )
{
  UINTN                                 Length;
  UINT8                                 *PtrBuf;
  UINTN                                 PtrEnd;

  PtrBuf      = Buffer;
  PtrEnd      = (UINTN)Buffer + BufferSize;

  //
  // 0x0D indicates a line break. Otherwise there is no line break
  //
  while ((UINTN)PtrBuf < PtrEnd) {
    if (*PtrBuf == 0x0D || *PtrBuf == 0x0A) {
      break;
    }
    PtrBuf++;
  }

  if ((UINTN)PtrBuf >= (PtrEnd - 1)) {
    //
    // The buffer ends without any line break
    // or it is the last character of the buffer
    //
    Length    = BufferSize;
  } else if (*(PtrBuf + 1) == 0x0A) {
    //
    // Further check if a 0x0A follows. If yes, count 0xA
    //
    Length    = (UINTN) PtrBuf - (UINTN) Buffer + 2;
  } else {
    Length    = (UINTN) PtrBuf - (UINTN) Buffer + 1;
  }

  if (Length > (*LineSize)) {
    *LineSize = Length;
    return EFI_BUFFER_TOO_SMALL;
  }

  SetMem (LineBuffer, *LineSize, 0x0);
  *LineSize   = Length;
  CopyMem (LineBuffer, Buffer, Length);

  return EFI_SUCCESS;
}

/**
  Trim Buffer by removing all CR, LF, TAB, and SPACE chars in its head and tail.

  @param[in, out] Buffer          On input,  buffer data to be trimed.
                                  On output, the trimmed buffer.
  @param[in, out] BufferSize      On input,  size of original buffer data.
                                  On output, size of the trimmed buffer.

**/
VOID
ProfileTrim (
  IN OUT  UINT8                         *Buffer,
  IN OUT  UINTN                         *BufferSize
  )
{
  UINTN                                 Length;
  UINT8                                 *PtrBuf;
  UINT8                                 *PtrEnd;

  if (*BufferSize == 0) {
    return;
  }

  //
  // Trim the tail first, include CR, LF, TAB, and SPACE.
  //
  Length          = *BufferSize;
  PtrBuf          = (UINT8 *) ((UINTN) Buffer + Length - 1);
  while (PtrBuf >= Buffer) {
    if ((*PtrBuf != 0x0D) && (*PtrBuf != 0x0A )
      && (*PtrBuf != 0x20) && (*PtrBuf != 0x09)) {
      break;
    }
    PtrBuf --;
  }

  //
  // all spaces, a blank line, return directly;
  //
  if (PtrBuf < Buffer) {
    *BufferSize   = 0;
    return;
  }

  Length          = (UINTN)PtrBuf - (UINTN)Buffer + 1;
  PtrEnd          = PtrBuf;
  PtrBuf          = Buffer;

  //
  // Now skip the heading CR, LF, TAB and SPACE
  //
  while (PtrBuf <= PtrEnd) {
    if ((*PtrBuf != 0x0D) && (*PtrBuf != 0x0A )
      && (*PtrBuf != 0x20) && (*PtrBuf != 0x09)) {
      break;
    }
    PtrBuf++;
  }

  //
  // If no heading CR, LF, TAB or SPACE, directly return
  //
  if (PtrBuf == Buffer) {
    *BufferSize   = Length;
    return;
  }

  *BufferSize     = (UINTN)PtrEnd - (UINTN)PtrBuf + 1;

  //
  // The first Buffer..PtrBuf characters are CR, LF, TAB or SPACE.
  // Now move out all these characters.
  //
  while (PtrBuf <= PtrEnd) {
    *Buffer       = *PtrBuf;
    Buffer++;
    PtrBuf++;
  }

  return;
}

/**
  Insert new comment item into comment head.

  @param[in]      Buffer          Comment buffer to be added.
  @param[in]      BufferSize      Size of comment buffer.
  @param[in, out] CommentHead     Comment Item head entry.

  @retval EFI_OUT_OF_RESOURCES   No enough memory is allocated.
  @retval EFI_SUCCESS            New comment item is inserted.

**/
EFI_STATUS
ProfileGetComments (
  IN      UINT8                         *Buffer,
  IN      UINTN                         BufferSize,
  IN OUT  COMMENT_LINE                  **CommentHead
  )
{
  COMMENT_LINE                          *CommentItem;

  CommentItem = NULL;
  CommentItem = AllocatePool (sizeof (COMMENT_LINE));
  if (CommentItem == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  CommentItem->PtrNext  = *CommentHead;
  *CommentHead          = CommentItem;

  //
  // Add a trailing '\0'
  //
  CommentItem->PtrComment = AllocatePool (BufferSize + 1);
  if (CommentItem->PtrComment == NULL) {
    FreePool (CommentItem);
    return EFI_OUT_OF_RESOURCES;
  }
  CopyMem (CommentItem->PtrComment, Buffer, BufferSize);
  *(CommentItem->PtrComment + BufferSize) = '\0';

  return EFI_SUCCESS;
}

/**
  Add new section item into Section head.

  @param[in]      Buffer          Section item data buffer.
  @param[in]      BufferSize      Size of section item.
  @param[in, out] SectionHead     Section item head entry.

  @retval EFI_OUT_OF_RESOURCES   No enough memory is allocated.
  @retval EFI_SUCCESS            Section item is NULL or Section item is added.

**/
EFI_STATUS
ProfileGetSection (
  IN      UINT8                         *Buffer,
  IN      UINTN                         BufferSize,
  IN OUT  SECTION_ITEM                  **SectionHead
  )
{
  SECTION_ITEM                          *SectionItem;
  UINTN                                 Length;
  UINT8                                 *PtrBuf;
  UINT8                                 *PtrEnd;

  ASSERT(BufferSize >= 1);
  //
  // The first character of Buffer is '[', now we want for ']'
  //
  PtrEnd      = (UINT8 *)((UINTN)Buffer + BufferSize - 1);
  PtrBuf      = (UINT8 *)((UINTN)Buffer + 1);
  while (PtrBuf <= PtrEnd) {
    if (*PtrBuf == ']') {
      break;
    }
    PtrBuf ++;
  }
  if (PtrBuf > PtrEnd) {
    //
    // Not found. Invalid line
    //
    return EFI_NOT_FOUND;
  }
  if (PtrBuf <= Buffer + 1) {
    // Empty name
    return EFI_NOT_FOUND;
  }

  //
  // excluding the heading '[' and tailing ']'
  //
  Length      = PtrBuf - Buffer - 1;
  ProfileTrim (
    Buffer + 1,
    &Length
  );

  //
  // Invalid line if the section name is null
  //
  if (Length == 0) {
    return EFI_NOT_FOUND;
  }

  if (!IsValidName((CHAR8 *)Buffer + 1, Length)) {
    return EFI_INVALID_PARAMETER;
  }

  SectionItem = AllocatePool (sizeof (SECTION_ITEM));
  if (SectionItem == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  SectionItem->PtrSection = NULL;
  SectionItem->SecNameLen = Length;
  SectionItem->PtrEntry   = NULL;
  SectionItem->PtrValue   = NULL;
  SectionItem->PtrNext    = *SectionHead;
  *SectionHead            = SectionItem;

  //
  // Add a trailing '\0'
  //
  SectionItem->PtrSection = AllocatePool (Length + 1);
  if (SectionItem->PtrSection == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  //
  // excluding the heading '['
  //
  CopyMem (SectionItem->PtrSection, Buffer + 1, Length);
  *(SectionItem->PtrSection + Length) = '\0';

  return EFI_SUCCESS;
}

/**
  Add new section entry and entry value into Section head.

  @param[in]      Buffer          Section entry data buffer.
  @param[in]      BufferSize      Size of section entry.
  @param[in, out] SectionHead     Section item head entry.

  @retval EFI_OUT_OF_RESOURCES   No enough memory is allocated.
  @retval EFI_SUCCESS            Section entry is added.
  @retval EFI_NOT_FOUND          Section entry is not found.
  @retval EFI_INVALID_PARAMETER  Section entry is invalid.

**/
EFI_STATUS
ProfileGetEntry (
  IN      UINT8                         *Buffer,
  IN      UINTN                         BufferSize,
  IN OUT  SECTION_ITEM                  **SectionHead
  )
{
  EFI_STATUS                            Status;
  SECTION_ITEM                          *SectionItem;
  SECTION_ITEM                          *PtrSection;
  UINTN                                 Length;
  UINT8                                 *PtrBuf;
  UINT8                                 *PtrEnd;

  Status      = EFI_SUCCESS;
  PtrBuf      = Buffer;
  PtrEnd      = (UINT8 *) ((UINTN)Buffer + BufferSize - 1);

  //
  // First search for '='
  //
  while (PtrBuf <= PtrEnd) {
    if (*PtrBuf == '=') {
      break;
    }
    PtrBuf++;
  }
  if (PtrBuf > PtrEnd) {
    //
    // Not found. Invalid line
    //
    return EFI_NOT_FOUND;
  }
  if (PtrBuf <= Buffer) {
    // Empty name
    return EFI_NOT_FOUND;
  }

  //
  // excluding the tailing '='
  //
  Length      = PtrBuf - Buffer;
  ProfileTrim (
    Buffer,
    &Length
  );

  //
  // Invalid line if the entry name is null
  //
  if (Length == 0) {
    return EFI_NOT_FOUND;
  }

  if (!IsValidName((CHAR8 *)Buffer, Length)) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // Omit this line if no section header has been found before
  //
  if (*SectionHead == NULL) {
    return Status;
  }
  PtrSection  = *SectionHead;

  SectionItem = AllocatePool (sizeof (SECTION_ITEM));
  if (SectionItem == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  SectionItem->PtrSection = NULL;
  SectionItem->PtrEntry   = NULL;
  SectionItem->PtrValue   = NULL;
  SectionItem->SecNameLen = PtrSection->SecNameLen;
  SectionItem->PtrNext    = *SectionHead;
  *SectionHead            = SectionItem;

  //
  // SectionName, add a trailing '\0'
  //
  SectionItem->PtrSection = AllocatePool (PtrSection->SecNameLen + 1);
  if (SectionItem->PtrSection == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }
  CopyMem (SectionItem->PtrSection, PtrSection->PtrSection, PtrSection->SecNameLen + 1);

  //
  // EntryName, add a trailing '\0'
  //
  SectionItem->PtrEntry = AllocatePool (Length + 1);
  if (SectionItem->PtrEntry == NULL) {
    FreePool(SectionItem->PtrSection);
    return EFI_OUT_OF_RESOURCES;
  }
  CopyMem (SectionItem->PtrEntry, Buffer, Length);
  *(SectionItem->PtrEntry + Length) = '\0';

  //
  // Next search for '#' or ';'
  //
  PtrBuf      = PtrBuf + 1;
  Buffer      = PtrBuf;
  while (PtrBuf <= PtrEnd) {
    if (*PtrBuf == '#' || *PtrBuf == ';') {
      break;
    }
    PtrBuf++;
  }
  if (PtrBuf <= Buffer) {
    // Empty name
    FreePool(SectionItem->PtrEntry);
    FreePool(SectionItem->PtrSection);
    return EFI_NOT_FOUND;
  }
  Length      = PtrBuf - Buffer;
  ProfileTrim (
    Buffer,
    &Length
  );

  //
  // Invalid line if the entry value is null
  //
  if (Length == 0) {
    FreePool(SectionItem->PtrEntry);
    FreePool(SectionItem->PtrSection);
    return EFI_NOT_FOUND;
  }

  if (!IsValidValue((CHAR8 *)Buffer, Length)) {
    FreePool(SectionItem->PtrEntry);
    FreePool(SectionItem->PtrSection);
    return EFI_INVALID_PARAMETER;
  }

  //
  // EntryValue, add a trailing '\0'
  //
  SectionItem->PtrValue = AllocatePool (Length + 1);
  if (SectionItem->PtrValue == NULL) {
    FreePool(SectionItem->PtrEntry);
    FreePool(SectionItem->PtrSection);
    return EFI_OUT_OF_RESOURCES;
  }
  CopyMem (SectionItem->PtrValue, Buffer, Length);
  *(SectionItem->PtrValue + Length) = '\0';

  return EFI_SUCCESS;
}

/**
  Free all comment entry and section entry.

  @param[in] Section         Section entry list.
  @param[in] Comment         Comment entry list.

**/
VOID
FreeAllList (
  IN      SECTION_ITEM                  *Section,
  IN      COMMENT_LINE                  *Comment
  )
{
  SECTION_ITEM                          *PtrSection;
  COMMENT_LINE                          *PtrComment;

  while (Section != NULL) {
    PtrSection    = Section;
    Section       = Section->PtrNext;
    if (PtrSection->PtrEntry != NULL) {
      FreePool (PtrSection->PtrEntry);
    }
    if (PtrSection->PtrSection != NULL) {
      FreePool (PtrSection->PtrSection);
    }
    if (PtrSection->PtrValue != NULL) {
      FreePool (PtrSection->PtrValue);
    }
    FreePool (PtrSection);
  }

  while (Comment != NULL) {
    PtrComment    = Comment;
    Comment       = Comment->PtrNext;
    if (PtrComment->PtrComment != NULL) {
      FreePool (PtrComment->PtrComment);
    }
    FreePool (PtrComment);
  }

  return;
}

/**
  Get section entry value.

  @param[in]  Section         Section entry list.
  @param[in]  SectionName     Section name.
  @param[in]  EntryName       Section entry name.
  @param[out] EntryValue      Point to the got entry value.

  @retval EFI_NOT_FOUND  Section is not found.
  @retval EFI_SUCCESS    Section entry value is got.

**/
EFI_STATUS
UpdateGetProfileString (
  IN      SECTION_ITEM                  *Section,
  IN      CHAR8                         *SectionName,
  IN      CHAR8                         *EntryName,
  OUT     CHAR8                         **EntryValue
  )
{
  *EntryValue   = NULL;

  while (Section != NULL) {
    if (AsciiStrCmp ((CONST CHAR8 *) Section->PtrSection, (CONST CHAR8 *) SectionName) == 0) {
      if (Section->PtrEntry != NULL) {
        if (AsciiStrCmp ((CONST CHAR8 *) Section->PtrEntry, (CONST CHAR8 *) EntryName) == 0) {
          break;
        }
      }
    }
    Section     = Section->PtrNext;
  }

  if (Section == NULL) {
    return EFI_NOT_FOUND;
  }

  *EntryValue   = Section->PtrValue;

  return EFI_SUCCESS;
}

/**
  Pre process config data buffer into Section entry list and Comment entry list.

  @param[in]      DataBuffer      Config raw file buffer.
  @param[in]      BufferSize      Size of raw buffer.
  @param[in, out] SectionHead     Pointer to the section entry list.
  @param[in, out] CommentHead     Pointer to the comment entry list.

  @retval EFI_OUT_OF_RESOURCES  No enough memory is allocated.
  @retval EFI_SUCCESS           Config data buffer is preprocessed.
  @retval EFI_NOT_FOUND         Config data buffer is invalid, because Section or Entry is not found.
  @retval EFI_INVALID_PARAMETER Config data buffer is invalid, because Section or Entry is invalid.

**/
EFI_STATUS
PreProcessDataFile (
  IN      UINT8                         *DataBuffer,
  IN      UINTN                         BufferSize,
  IN OUT  SECTION_ITEM                  **SectionHead,
  IN OUT  COMMENT_LINE                  **CommentHead
  )
{
  EFI_STATUS                            Status;
  CHAR8                                 *Source;
  CHAR8                                 *CurrentPtr;
  CHAR8                                 *BufferEnd;
  CHAR8                                 *PtrLine;
  UINTN                                 LineLength;
  UINTN                                 SourceLength;
  UINTN                                 MaxLineLength;

  *SectionHead          = NULL;
  *CommentHead          = NULL;
  BufferEnd             = (CHAR8 *) ( (UINTN) DataBuffer + BufferSize);
  CurrentPtr            = (CHAR8 *) DataBuffer;
  MaxLineLength         = MAX_LINE_LENGTH;
  Status                = EFI_SUCCESS;

  PtrLine = AllocatePool (MaxLineLength);
  if (PtrLine == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  while (CurrentPtr < BufferEnd) {
    Source              = CurrentPtr;
    SourceLength        = (UINTN)BufferEnd - (UINTN)CurrentPtr;
    LineLength          = MaxLineLength;
    //
    // With the assumption that line length is less than 512
    // characters. Otherwise BUFFER_TOO_SMALL will be returned.
    //
    Status              = ProfileGetLine (
                            (UINT8 *) Source,
                            SourceLength,
                            (UINT8 *) PtrLine,
                            &LineLength
                            );
    if (EFI_ERROR (Status)) {
      if (Status == EFI_BUFFER_TOO_SMALL) {
        //
        // If buffer too small, re-allocate the buffer according
        // to the returned LineLength and try again.
        //
        FreePool (PtrLine);
        PtrLine         = NULL;
        PtrLine = AllocatePool (LineLength);
        if (PtrLine == NULL) {
          Status        = EFI_OUT_OF_RESOURCES;
          break;
        }
        SourceLength    = LineLength;
        Status          = ProfileGetLine (
                            (UINT8 *) Source,
                            SourceLength,
                            (UINT8 *) PtrLine,
                            &LineLength
                            );
        if (EFI_ERROR (Status)) {
          break;
        }
        MaxLineLength   = LineLength;
      } else {
        break;
      }
    }
    CurrentPtr          = (CHAR8 *) ( (UINTN) CurrentPtr + LineLength);

    //
    // Line got. Trim the line before processing it.
    //
    ProfileTrim (
      (UINT8 *) PtrLine,
      &LineLength
   );

    //
    // Blank line
    //
    if (LineLength == 0) {
      continue;
    }

    if (PtrLine[0] == '#' || PtrLine[0] == ';') {
      Status            = ProfileGetComments (
                            (UINT8 *) PtrLine,
                            LineLength,
                            CommentHead
                            );
    } else if (PtrLine[0] == '[') {
      Status            = ProfileGetSection (
                            (UINT8 *) PtrLine,
                            LineLength,
                            SectionHead
                            );
    } else {
      Status            = ProfileGetEntry (
                            (UINT8 *) PtrLine,
                            LineLength,
                            SectionHead
                            );
    }

    if (EFI_ERROR (Status)) {
      break;
    }
  }

  //
  // Free buffer
  //
  FreePool (PtrLine);

  return Status;
}

/**
  Open an INI config file and return a context.

  @param[in] DataBuffer      Config raw file buffer.
  @param[in] BufferSize      Size of raw buffer.

  @return       Config data buffer is opened and context is returned.
  @retval NULL  No enough memory is allocated.
  @retval NULL  Config data buffer is invalid.
**/
VOID *
EFIAPI
OpenIniFile (
  IN      UINT8                         *DataBuffer,
  IN      UINTN                         BufferSize
  )
{
  EFI_STATUS                            Status;
  INI_PARSING_LIB_CONTEXT               *IniContext;

  if (DataBuffer == NULL || BufferSize == 0) {
    return NULL;
  }

  IniContext = AllocateZeroPool(sizeof(INI_PARSING_LIB_CONTEXT));
  if (IniContext == NULL) {
    return NULL;
  }

  //
  // First process the data buffer and get all sections and entries
  //
  Status = PreProcessDataFile (
             DataBuffer,
             BufferSize,
             &IniContext->SectionHead,
             &IniContext->CommentHead
             );
  if (EFI_ERROR(Status)) {
    FreePool(IniContext);
    return NULL;
  }
  DEBUG_CODE_BEGIN ();
    DumpIniSection(IniContext);
  DEBUG_CODE_END ();
  return IniContext;
}

/**
  Get section entry string value.

  @param[in]  Context         INI Config file context.
  @param[in]  SectionName     Section name.
  @param[in]  EntryName       Section entry name.
  @param[out] EntryValue      Point to the got entry string value.

  @retval EFI_SUCCESS    Section entry string value is got.
  @retval EFI_NOT_FOUND  Section is not found.
**/
EFI_STATUS
EFIAPI
GetStringFromDataFile(
  IN      VOID                          *Context,
  IN      CHAR8                         *SectionName,
  IN      CHAR8                         *EntryName,
  OUT     CHAR8                         **EntryValue
  )
{
  INI_PARSING_LIB_CONTEXT               *IniContext;
  EFI_STATUS                            Status;

  if (Context == NULL || SectionName == NULL || EntryName == NULL || EntryValue == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  IniContext = Context;

  *EntryValue  = NULL;
  Status = UpdateGetProfileString (
             IniContext->SectionHead,
             SectionName,
             EntryName,
             EntryValue
             );
  return Status;
}

/**
  Get section entry GUID value.

  @param[in]  Context         INI Config file context.
  @param[in]  SectionName     Section name.
  @param[in]  EntryName       Section entry name.
  @param[out] Guid            Point to the got GUID value.

  @retval EFI_SUCCESS    Section entry GUID value is got.
  @retval EFI_NOT_FOUND  Section is not found.
**/
EFI_STATUS
EFIAPI
GetGuidFromDataFile (
  IN      VOID                          *Context,
  IN      CHAR8                         *SectionName,
  IN      CHAR8                         *EntryName,
  OUT     EFI_GUID                      *Guid
  )
{
  CHAR8                                 *Value;
  EFI_STATUS                            Status;
  RETURN_STATUS                         RStatus;

  if (Context == NULL || SectionName == NULL || EntryName == NULL || Guid == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Status = GetStringFromDataFile(
             Context,
             SectionName,
             EntryName,
             &Value
             );
  if (EFI_ERROR(Status)) {
    return EFI_NOT_FOUND;
  }
  ASSERT (Value != NULL);
  RStatus = AsciiStrToGuid (Value, Guid);
  if (RETURN_ERROR (RStatus) || (Value[GUID_STRING_LENGTH] != '\0')) {
    return EFI_NOT_FOUND;
  }
  return EFI_SUCCESS;
}

/**
  Get section entry decimal UINTN value.

  @param[in]  Context         INI Config file context.
  @param[in]  SectionName     Section name.
  @param[in]  EntryName       Section entry name.
  @param[out] Data            Point to the got decimal UINTN value.

  @retval EFI_SUCCESS    Section entry decimal UINTN value is got.
  @retval EFI_NOT_FOUND  Section is not found.
**/
EFI_STATUS
EFIAPI
GetDecimalUintnFromDataFile (
  IN      VOID                          *Context,
  IN      CHAR8                         *SectionName,
  IN      CHAR8                         *EntryName,
  OUT     UINTN                         *Data
  )
{
  CHAR8                                 *Value;
  EFI_STATUS                            Status;

  if (Context == NULL || SectionName == NULL || EntryName == NULL || Data == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Status = GetStringFromDataFile(
             Context,
             SectionName,
             EntryName,
             &Value
             );
  if (EFI_ERROR(Status)) {
    return EFI_NOT_FOUND;
  }
  ASSERT (Value != NULL);
  if (!IsValidDecimalString(Value, AsciiStrLen(Value))) {
    return EFI_NOT_FOUND;
  }
  *Data = AsciiStrDecimalToUintn(Value);
  return EFI_SUCCESS;
}

/**
  Get section entry heximal UINTN value.

  @param[in]  Context         INI Config file context.
  @param[in]  SectionName     Section name.
  @param[in]  EntryName       Section entry name.
  @param[out] Data            Point to the got heximal UINTN value.

  @retval EFI_SUCCESS    Section entry heximal UINTN value is got.
  @retval EFI_NOT_FOUND  Section is not found.
**/
EFI_STATUS
EFIAPI
GetHexUintnFromDataFile (
  IN      VOID                          *Context,
  IN      CHAR8                         *SectionName,
  IN      CHAR8                         *EntryName,
  OUT     UINTN                         *Data
  )
{
  CHAR8                                 *Value;
  EFI_STATUS                            Status;

  if (Context == NULL || SectionName == NULL || EntryName == NULL || Data == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Status = GetStringFromDataFile(
             Context,
             SectionName,
             EntryName,
             &Value
             );
  if (EFI_ERROR(Status)) {
    return EFI_NOT_FOUND;
  }
  ASSERT (Value != NULL);
  if (!IsValidHexString(Value, AsciiStrLen(Value))) {
    return EFI_NOT_FOUND;
  }
  *Data = AsciiStrHexToUintn(Value);
  return EFI_SUCCESS;
}

/**
  Get section entry heximal UINT64 value.

  @param[in]  Context         INI Config file context.
  @param[in]  SectionName     Section name.
  @param[in]  EntryName       Section entry name.
  @param[out] Data            Point to the got heximal UINT64 value.

  @retval EFI_SUCCESS    Section entry heximal UINT64 value is got.
  @retval EFI_NOT_FOUND  Section is not found.
**/
EFI_STATUS
EFIAPI
GetHexUint64FromDataFile (
  IN      VOID                          *Context,
  IN      CHAR8                         *SectionName,
  IN      CHAR8                         *EntryName,
  OUT     UINT64                        *Data
  )
{
  CHAR8                                 *Value;
  EFI_STATUS                            Status;

  if (Context == NULL || SectionName == NULL || EntryName == NULL || Data == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Status = GetStringFromDataFile(
             Context,
             SectionName,
             EntryName,
             &Value
             );
  if (EFI_ERROR(Status)) {
    return EFI_NOT_FOUND;
  }
  ASSERT (Value != NULL);
  if (!IsValidHexString(Value, AsciiStrLen(Value))) {
    return EFI_NOT_FOUND;
  }
  *Data = AsciiStrHexToUint64(Value);
  return EFI_SUCCESS;
}

/**
  Close an INI config file and free the context.

  @param[in] Context         INI Config file context.
**/
VOID
EFIAPI
CloseIniFile (
  IN      VOID                          *Context
  )
{
  INI_PARSING_LIB_CONTEXT               *IniContext;

  if (Context == NULL) {
    return ;
  }

  IniContext = Context;
  FreeAllList(IniContext->SectionHead, IniContext->CommentHead);

  return;
}
